Microsoft distributes Microsoft SQL Server 2012 fixes as one downloadable file. Because the fixes are cumulative, each new release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2012 fix release.
Symptoms
Assume that multiple I/O-intensive tasks run at the same time in Microsoft SQL Server 2012. Then, the idle scheduler signals worker threads to resume their tasks. However, the worker threads do not wake immediately.
Resolution
Cumulative update information
Cumulative update package 1 for SQL Server 2012 Service Pack 1
The fix for this issue was first released in Cumulative Update 1. For more information about how to obtain this cumulative update package for SQL Server 2012 Service Pack 1, click the following article number to view the article in the Microsoft Knowledge Base:
2765331 Cumulative update package 1 for SQL Server 2012 Service Pack 1Note Because the builds are cumulative, each new fix release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2012 fix release. We recommend that you consider applying the most recent fix release that contains this hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
2772858 The SQL Server 2012 builds that were released after SQL Server 2012 Service Pack 1 was released
Cumulative update package 4 for SQL Server 2012
The fix for this issue was first released in Cumulative Update 4. For more information about how to obtain this cumulative update package for SQL Server 2012, click the following article number to view the article in the Microsoft Knowledge Base:
2758687 Cumulative update 4 for SQL Server 2012Note Because the builds are cumulative, each new fix release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2012 fix release. We recommend that you consider applying the most recent fix release that contains this hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
2692828 The SQL Server 2012 builds that were released after SQL Server 2012 was released
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
For more information the Incremental Servicing Model for SQL Server, click the following article number to view the article in the Microsoft Knowledge Base:
935897 An Incremental Servicing Model is available from the SQL Server team to deliver hotfixes for reported problems For more information about the naming schema for SQL Server updates, click the following article number to view the article in the Microsoft Knowledge Base:
822499 Naming schema for Microsoft SQL Server software update packages For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates